A laminated coil device and a method of manufacturing the same

Abstract

This application discloses a laminated coil device and its fabrication method. The laminated coil device includes a laminate body and an external electrode. The laminate body includes a marking layer and a lead-out layer stacked sequentially. The lead-out layer includes at least one lead-out unit, which includes a lead-out electrode and a dielectric layer. The lead-out electrode and the dielectric layer are stacked together. A crack is provided on the lead-out unit near the marking layer, and the crack is located between the lead-out electrode and the dielectric layer of the lead-out unit. The external electrode paste of the external electrode enters the crack and connects to the corresponding lead-out electrode. This application can enhance the bonding force between the external electrode and the lead-out electrode, reduce the risk of open circuits or loose connections in the laminated coil device, and improve the reliability of the product and the yield rate of mass production.

Description

Technical Field

[0001] This application relates to the field of electronic component technology, and in particular to a stacked coil device and its fabrication method. Background Technology

[0002] As electronic devices develop towards higher frequencies, smaller sizes, and higher power densities, inductors, as key passive components, directly affect the overall performance of circuit systems due to their stability and reliability. Among the many factors influencing the electrical performance of inductors, the connection between the internal and external electrodes is one of the core factors determining inductor performance, directly related to the inductor's conduction efficiency, signal transmission stability, and long-term operating durability.

[0003] To improve electrode connection performance, various optimization measures have been adopted in related technologies, including selecting suitable electrode materials, cleaning and activating electrode surfaces, and reducing electrode layer porosity by improving sintering processes. However, for laminated coil devices, the external electrode paste can only achieve surface bonding with the electrode leads on the device surface. If the electrode lead surface is covered by ceramic, has contaminant adhesion, or the lead itself has defects such as broken wires or burn-out, it can easily lead to open circuits or loose connections in the laminated coil device, affecting the reliability of the device and the yield rate of mass production. Summary of the Invention

[0004] This application aims to at least solve one of the aforementioned technical problems existing in the prior art. Therefore, the purpose of this application is to provide a laminated coil device that enhances the bonding force between the external electrode and the lead electrode, reduces the risk of open circuits or false connections in the laminated coil device, and improves the reliability of the product and the yield rate of mass production.

[0005] This application also proposes a method for fabricating the above-mentioned stacked coil device.

[0006] The stacked coil device according to a first aspect embodiment of this application includes: A laminate comprising a marker layer and an lead-out layer stacked sequentially, the lead-out layer comprising at least one lead-out unit, the lead-out unit comprising a lead-out electrode and a dielectric layer, the lead-out electrode being stacked with the dielectric layer, and the lead-out unit on the side of the lead-out layer near the marker layer having a crack, the crack being disposed between the lead-out electrode of the lead-out unit and the dielectric layer. An external electrode, wherein the external electrode slurry of the external electrode enters the crack and connects to the corresponding lead-out electrode.

[0007] The stacked coil device according to the embodiments of this application has at least the following beneficial effects: a crack is provided in the lead-out unit near the marking layer in the lead-out layer of the stacked body, and the crack is specifically located between the lead-out electrode of the lead-out unit and the dielectric layer. When the external electrode paste of the external electrode is coated, the external electrode paste can enter the interior of the crack, thereby connecting with the corresponding lead-out electrode, enhancing the bonding force between the external electrode and the lead-out electrode, reducing the risk of open circuit or false connection in the stacked coil device, and improving the reliability of the product and the pass rate of mass production.

[0008] According to some embodiments of this application, the crack extends inward from the end corresponding to the lead-out electrode.

[0009] According to some embodiments of this application, the width of the crack is denoted as w, and the width w of the crack satisfies the relationship: 30μm≤w≤the end width of the lead-out electrode.

[0010] According to some embodiments of this application, the length of the crack is denoted as... l The length l of the crack satisfies the following relationship: 5μm ≤ l ≤20μm.

[0011] According to some embodiments of this application, the height of the crack is denoted as h, and the height h of the crack satisfies the relationship: 2μm≤h≤5μm.

[0012] According to some embodiments of this application, the thickness of the marking layer is set to 10 μm to 30 μm.

[0013] According to some embodiments of this application, the thickness of the lead-out electrode is set to 15 μm to 25 μm.

[0014] According to some embodiments of this application, the thickness of the dielectric layer is set to 10 μm to 20 μm.

[0015] According to some embodiments of this application, the laminate further includes an insulating layer, an introduction layer, and an effective electrode region, wherein the insulating layer, the introduction layer, the effective electrode region, the lead-out layer, and the marking layer are stacked sequentially.

[0016] According to some embodiments of this application, the thickness of the marking layer is less than the thickness of the insulating layer.

[0017] The preparation method according to the second aspect embodiment of this application, based on the stacked coil device of the first aspect embodiment of this application, includes the following steps: Prepare dielectric layer slurry, internal electrode slurry, and marker layer slurry according to the formula; The dielectric layer slurry is used to form the dielectric layer; The lead-out electrode is fabricated on the dielectric layer using a first screen and the internal electrode paste to form the lead-out unit; The marking layer is made using a second screen and the marking layer slurry; The extraction unit and the marking layer are stacked in a preset stacking order to form a stacked overall structure; The stacked whole is cut into multiple stacked blanks such that the lead-out unit on the side of the lead-out layer near the mark layer forms the crack; The laminated body green body is sintered to obtain the laminated body; The laminated body is connected to the external electrode to obtain the laminated coil device.

[0018] The preparation method according to the embodiments of this application has at least the following beneficial effects: By forming the dielectric layer slurry into a dielectric layer, and using a first screen and a second screen to respectively fabricate the lead-out electrode and the marking layer, during the process of stacking the lead-out unit and the marking layer in a preset stacking order and cutting them into multiple laminated green bodies, cracks can be formed in the lead-out unit on the side of the lead-out layer close to the marking layer. Crack formation can be achieved without additional complex processing steps, simplifying the preparation process of the laminated coil device and improving mass production efficiency. Simultaneously, when the laminated body is subsequently sintered and connected to the external electrode, the external electrode slurry of the external electrode can enter the crack and connect with the corresponding lead-out electrode, improving the reliability of the connection between the internal and external electrodes of the laminated coil device, reducing the risk of open circuits and false connections in the laminated coil device, thereby improving the overall quality of the product and the mass production qualification rate.

[0019] According to some embodiments of this application, cutting the laminated whole into multiple laminated green bodies such that the lead-out unit on the side of the lead-out layer near the marker layer forms the crack includes: The cutting blade is pressed into the stacked assembly; The cutting blade separates from the overall stack, and the crack is generated between the lead-out electrode and the corresponding dielectric layer.

[0020] According to some embodiments of this application, sintering the laminated green body to obtain the laminated body includes: The green body of the laminate is sintered at 800℃~900℃ and held for 20min~100min to form the laminate.

[0021] According to some embodiments of this application, connecting the laminate to the external electrode includes: The two ends of the sintered laminate are coated with the external electrode slurry, and the external electrode slurry enters the crack; The laminate is sintered at 500℃ to 700℃ and held at that temperature for 5 min to 20 min, so that the two ends of the laminate form the external electrodes.

[0022] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0023] The present application will be further described below with reference to the accompanying drawings and embodiments, wherein: Figure 1 This is one of the structural schematic diagrams of the stacked coil device according to an embodiment of this application; Figure 2 This is a second schematic diagram of the structure of the stacked coil device according to an embodiment of this application; Figure 3 This is a partial structural schematic diagram of the stacked coil device according to an embodiment of this application; Figure 4 This is a schematic diagram of the stacked structure of the embodiment of this application; Figure 5 This is a schematic flowchart of the preparation method in the embodiments of this application.

[0024] Reference numerals: 100, laminate; 110, marker layer; 120, lead-out layer; 121, lead-out electrode; 122, dielectric layer; 130, crack; 140, insulating layer; 150, introduction layer; 160, effective electrode region; 200, External electrode; 210, External electrode slurry. Detailed Implementation

[0025] The embodiments of this application are described in detail below. Examples of these embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0026] In the description of this application, it should be understood that the orientation descriptions, such as up, down, front, back, left, right, etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application.

[0027] In the description of this application, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. The use of "first" and "second" in the description is merely for distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0028] In the description of this application, unless otherwise expressly defined, terms such as "setup," "installation," and "connection" should be interpreted broadly, and those skilled in the art can reasonably determine the specific meaning of the above terms in this application in conjunction with the specific content of the technical solution.

[0029] In the description of this application, the terms "one embodiment," "some embodiments," "illustrative embodiment," "example," "specific example," or "some examples," etc., refer to specific features, structures, materials, or characteristics described in connection with that embodiment or example, which are included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0030] Reference Figure 1 and Figure 2 The first aspect of this application provides a stacked coil device, including a stacked body 100 and an external electrode 200. The stacked body 100 includes a marking layer 110 and a lead-out layer 120 stacked sequentially. The lead-out layer 120 includes at least one lead-out unit, which includes a lead-out electrode 121 and a dielectric layer 122. The lead-out electrode 121 and the dielectric layer 122 are stacked together. A crack 130 is provided on the lead-out unit of the lead-out layer 120 near the marking layer 110. The crack 130 is located between the lead-out electrode 121 and the dielectric layer 122 of the lead-out unit. The external electrode paste 210 of the external electrode 200 enters the crack 130 and connects with the corresponding lead-out electrode 121.

[0031] Specifically, in the lead-out layer 120 of the laminate 100, a crack 130 is provided in the lead-out unit near the marking layer 110. The crack 130 is specifically located between the lead-out electrode 121 and the dielectric layer 122 of the lead-out unit. When the external electrode paste 210 of the external electrode 200 is coated, the external electrode paste 210 can enter the interior of the crack 130, thereby connecting with the corresponding lead-out electrode 121, enhancing the bonding force between the external electrode 200 and the lead-out electrode 121, reducing the risk of open circuit or false connection in the laminated coil device, and improving the reliability of the product and the pass rate of mass production.

[0032] In some embodiments, the crack 130 extends inward from the end of the corresponding lead electrode 121, which can increase the effective contact area between the external electrode paste 210 and the lead electrode 121, extend the bonding path between the external electrode paste 210 and the lead electrode 121, improve the bonding strength and conductivity stability between the inner and outer electrodes of the laminated coil device, and further reduce the adverse effects on electrical connection caused by the electrode lead end surface being covered by ceramic, the presence of contaminant adhesion, or defects such as broken wires or burns at the lead end, improve the reliability of the conduction between the inner and outer electrodes of the laminated coil device, reduce the probability of open circuits or loose connections in the laminated coil device during use, and improve the overall electrical performance and service life of the product.

[0033] It should be noted that the length of crack 130... l、 The width w and height h (defined according to the length, width, and height directions of the laminated coil device) are jointly determined by the thickness of the lead electrode 121 of the lead layer 120, the thickness of the dielectric layer 122 of the lead layer 120, and the thickness of the marking layer 110. The length of the crack 130... l、 If the width w and height h exceed the aforementioned numerical range, the size of crack 130 will exceed the design dimensions. If the size of crack 130 is smaller than the design dimensions, crack 130 will not be able to improve the bonding strength between the inner and outer electrodes of the laminated coil device. If the height of crack 130 exceeds the design height, the outer electrode paste 210 of the outer electrode 200 will directly contact the inner coil electrode of the laminated coil device, causing a short circuit. In addition, crack 130 may also directly cut off the inner coil of the laminated coil device, causing an open circuit, damaging the inner coil of the laminated coil device, changing the shape and number of turns of the inner coil, and causing the inductance value to deviate from the set value. Secondly, if the size of crack 130 is too large, it will also reduce the mechanical strength of the laminated coil device. At the same time, uncontrollable crack 130 may change the relative position and electric field distribution between the inner electrodes of the laminated coil device, introducing unpredictable parasitic capacitance. The additional parasitic capacitance will reduce the Q value (quality factor) and reduce the self-resonant frequency of the inductor, limiting its usable range at high frequencies.

[0034] Reference Figures 1 to 3 In some embodiments, the width of the crack 130 is denoted as w, and the width w of the crack 130 satisfies the relationship: 30μm ≤ w ≤ the end width of the lead-out electrode 121. Preferably, the width w of the crack 130 is set to 50μm to 80μm. The width w of the crack 130 can be designed to be any value in the range of 50μm, 55μm, 60μm, 65μm, 70μm, 75μm, 80μm, etc. In actual design, the size of the width w of the crack 130 can be designed according to actual needs. It should be noted that the end width of the lead-out electrode 121 is the width of the portion of the lead-out electrode 121 that extends out of the laminate 100 and connects with the external electrode.

[0035] Reference Figures 1 to 3 In some embodiments, the length of crack 130 is denoted as l The length of the crack is 130. l Satisfies the relation: 5μm≤ l ≤20μm. Preferably, the length of the crack 130 is... l Setting the crack width to 10μm to 15μm allows for the design of crack lengths up to 130 mm. l The crack length can be any value within the range of 10μm, 11μm, 12μm, 13μm, 14μm, and 15μm. In actual design, the length of crack 130 can be designed according to actual needs. l The size of the crack. It should be noted that the length of crack 130... l The length of the crack 130 extending inward.

[0036] Reference Figures 1 to 3 In some embodiments, the height of crack 130 is denoted as h, and the height h of crack 130 satisfies the relationship: 2μm≤h≤5μm. Preferably, the height h of crack 130 is set to 3μm~4μm, and the height h of crack 130 can be designed to be any value in the range of 3μm, 3.1μm, 3.2μm, 3.3μm, 3.4μm, 3.5μm, 3.6μm, 3.7μm, 3.8μm, 3.9μm, 4μm, etc. In actual design, the size of the height h of crack 130 can be designed according to actual needs.

[0037] This application sets clear numerical ranges and preferred intervals for the width, length, and height of the crack 130, and provides specific selectable values. This enables the refined and quantitative design of the crack 130, ensuring that the parameters of each dimension of the crack 130 are compatible with the width of the lead electrode 121 and the overall structure of the laminate 100. This ensures that the external electrode paste 210 of the external electrode 200 can enter the crack 130 and form a stable bond with the lead electrode 121, improving the connection strength and conductivity reliability of the internal and external electrodes. At the same time, it avoids problems such as short circuits, open circuits, inductance value shifts, Q value decreases, self-resonant frequency reductions, and insufficient mechanical strength of the device caused by the crack 130 being too large. It also prevents the external electrode paste 210 from being poorly filled and having poor connection effects due to its small size.

[0038] It should be noted that the thickness of the marking layer 110 affects whether the crack 130 can form and whether the crack 130 is controllable. If the thickness of the marking layer 110 is greater than the design range, the lead-out layer 120 will be subject to greater binding force, and the crack 130 may not form or may be too shallow (the length, width, and height of the crack 130 may not meet the requirements), making it impossible to form an effective channel for the external electrode paste 210 to be poured in. If the thickness of the marking layer 110 is less than the design range, the marking layer 110 will be too thin, resulting in stress concentration and making it easy to form a deep, narrow, and uncontrollable crack 130. The internal coils of the stacked coil device are easily damaged, leading to changes in inductance or product failure. At the same time, sharp stress may cause the crack 130 to branch, making the path unpredictable and increasing the risk of failure. In addition, if the thickness of the marking layer 110 is less than the design range, it will reduce the mechanical strength of the marking layer 110, making the product more fragile after cutting and prone to overall breakage during transportation and termination.

[0039] In some embodiments, the thickness of the marking layer 110 is set to 10μm to 30μm. Preferably, the thickness of the marking layer 110 is set to 15μm to 20μm. The thickness of the marking layer 110 can be set to any value in the range of 15μm, 15.5μm, 16μm, 16.5μm, 17μm, 17.5μm, 18μm, 18.5μm, 19μm, 19.5μm, 20μm, etc. In actual design, the thickness of the marking layer 110 can be designed according to actual needs.

[0040] This application, by limiting the thickness of the marking layer 110 to a reasonable range and setting an optimal interval, can control the stress distribution and binding force generated during the molding process of the laminated structure. This ensures that cracks 130 are formed in the lead-out units on the side of the lead-out layer 120 near the marking layer 110, avoiding the situation where the marking layer 110 is too thick, causing cracks 130 to fail to form or to be too small to form a channel for the external electrode slurry 210 to enter. At the same time, it prevents stress concentration caused by the marking layer 110 being too thin, which could lead to problems such as excessively deep cracks 130, bifurcations, uncontrollable paths, damage to internal coils, inductance value deviation, and product failure. It can also improve the mechanical strength of the marking layer 110 itself, reduce the probability of overall fracture of the laminated body 100 during cutting, transportation, and termination processes, and ensure that the crack 130 structure and the overall laminated structure remain stable and reliable throughout the entire manufacturing process. This provides a structural basis for the smooth entry of the external electrode slurry 210 of the external electrode 200 into the crack 130 and its connection with the lead-out electrode 121.

[0041] It should be noted that the thickness of the lead-out layer 120 is the sum of the thickness of the lead-out electrode 121 and the thickness of its dielectric layer 122. If the lead-out electrode 121 is too thin, its structural strength will be low, and the interface between it and the adjacent dielectric layer 122 will be weak. During cutting, the lead-out electrode 121 is prone to delamination from the surrounding dielectric layer 122, and the cutting blade may easily "remove" the lead-out electrode 121, preventing the formation of cracks 130 for the external electrode paste 210 to enter, thus limiting the improvement of the internal and external electrode connectivity of the laminated coil device. At the same time, if the lead-out electrode 121 is too thin, the lead-out end of the lead-out electrode 121 may be damaged, increasing the risk of poor connection between the internal and external electrodes of the laminated coil device. Furthermore, if the lead-out electrode 121 is overheated, the lead-out end of the lead-out electrode 121 is easily burned off, resulting in an open circuit or a loose connection. Furthermore, if the lead-out electrode 121 is too thick, stress concentration will occur between the lead-out electrode 121 and the dielectric layer 122. During cutting, the crack 130 will tend to bypass or penetrate the lead-out electrode 121 and extend into the dielectric layer 122. Moreover, the extension process is prone to branching, and the path is unpredictable, which can easily damage the lead-out electrode 121. In addition, if the lead-out electrode 121 is too thick, its mechanical strength will be greatly reduced, and the crack 130 will be large. This will lead to a mismatch between the sintering shrinkage of the lead-out electrode 121 and the dielectric layer 122 during sintering, which can easily cause other types of internal cracking.

[0042] In some embodiments, the thickness of the lead-out electrode 121 in the lead-out layer 120 is set to 15μm to 25μm. Preferably, the thickness of the lead-out electrode 121 is set to 17μm to 22μm. The thickness of the lead-out electrode 121 can be set to any value in the range of 17μm, 17.5μm, 18μm, 18.5μm, 19μm, 19.5μm, 20μm, 20.5μm, 21μm, 21.5μm, 22μm, etc. In actual design, the thickness of the lead-out electrode 121 can be designed according to actual needs.

[0043] This application controls the thickness of the lead-out electrode 121 within a set range and selects an optimal interval, which ensures that the lead-out electrode 121 has appropriate structural strength, improves the bonding interface strength between the lead-out electrode 121 and the adjacent dielectric layer 122, avoids delamination or removal of the lead-out electrode 121 by the cutting blade during the cutting process, ensures the stable formation of the crack 130 that allows the external electrode paste 210 to enter, improves the connection performance between the internal and external electrodes of the laminated coil device, reduces the probability of damage to the lead-out end of the lead-out electrode 121, reduces the risk of poor connection between the internal and external electrodes, and avoids the lead-out end from overheating when the lead-out electrode 121 is burned out. The open circuit or loose connection problem caused by burn-out can also alleviate the stress concentration between the lead electrode 121 and the dielectric layer 122, prevent the crack 130 from spreading irregularly, branching and penetrating the lead electrode 121 during cutting, reduce damage to the lead electrode 121, ensure that the lead electrode 121 and the dielectric layer 122 shrink in a consistent manner during sintering, avoid internal cracking caused by shrinkage differences, improve the overall stability of the laminated structure, and thus ensure that the laminated coil device maintains good structural integrity and electrical connection reliability during preparation, transportation and use, and improve product qualification rate and long-term use stability.

[0044] It should be noted that if the dielectric layer 122 is too thin, it will have almost no buffering capacity. During cutting, the cutting stress will act directly on the interface of the lead electrode 121 with extremely high energy density and spread rapidly downward, penetrating the dielectric layer 122 and the lead electrode 121 itself, and may even extend to the inner electrode coil below, thus leading to the risk of open circuit or short circuit and failing to guide the formation of crack 130. If the dielectric layer 122 is too thick, during cutting, the cutting stress will be largely consumed and dispersed due to plastic deformation when passing through the thicker dielectric layer 122. When the stress propagates to the interface between the lead-out electrode 121 and its dielectric layer 122, its energy is insufficient to drive the crack 130 to form or stops as soon as it forms, thus failing to improve the connection between the inner and outer electrodes. At the same time, if the dielectric layer 122 is too thick, the crack 130 path is prone to deflection out of control. The thicker dielectric layer 122 provides the crack 130 with a longer propagation path and more options. During the propagation of the crack 130, it is easily affected by the micro-inhomogeneity of the material (such as pores and grain boundaries), thus deviating from the formation of the preset crack 130 and potentially introducing unnecessary damage.

[0045] In some embodiments, the thickness of the dielectric layer 122 in the lead-out layer 120 is set to 10μm to 20μm. Preferably, the thickness of the dielectric layer 122 is set to 13μm to 15μm. The thickness of the dielectric layer 122 can be set to any value in the range of 13μm, 13.2μm, 13.4μm, 13.6μm, 13.8μm, 14μm, 14.2μm, 14.4μm, 14.6μm, 14.8μm, 15μm, etc. In actual design, the thickness of the dielectric layer 122 can be designed according to actual needs.

[0046] This application controls the thickness of the dielectric layer 122 within a set range and selects an optimal interval, which enables the cutting stress to maintain a suitable intensity and propagation path during propagation. This avoids the situation where the dielectric layer 122 is too thin, resulting in insufficient buffering capacity. In this case, the cutting stress would directly act on the interface of the lead-out electrode 121 and extend downwards to the inner electrode coil below, potentially causing open circuits, short circuits, and preventing the formation of a regular crack 130. Simultaneously, it prevents the dielectric layer 122 from being too thick, causing excessive consumption and dispersion of the cutting stress, which could prevent the crack 130 from forming or terminate prematurely. This ensures that the crack 130 can be formed between the lead-out electrode 121 and the dielectric layer. The dielectric layers 122 are reliably generated in a preset direction, which improves the connection effect between the inner and outer electrodes. It can also avoid the problems of uncontrolled crack path, deflection and deviation from the preset trajectory caused by excessive thickness of the dielectric layer 122. It reduces the interference of micro-inhomogeneity of materials on the formation of crack 130, reduces unnecessary internal damage, improves the stability and consistency of the laminated structure in the cutting process, and provides structural guarantee for the subsequent filling of the outer electrode 200 and the connection with the lead electrode 121. It further improves the fabrication yield, electrical performance stability and long-term reliability of the laminated coil device.

[0047] Reference Figure 1 , Figure 4 In some embodiments, the laminate 100 further includes an insulating layer 140, an introduction layer 150, and an effective electrode region 160, wherein the insulating layer 140, the introduction layer 150, the effective electrode region 160, the lead-out layer 120, and the marker layer 110 are sequentially stacked. The insulating layer 140 is composed of at least one dielectric layer 122, and the marker layer 110 is composed of one dielectric layer 122, which enhances the overall insulation performance of the laminate 100 and avoids the risk of interlayer leakage and short circuits. Furthermore, the effective electrode region 160 is formed by alternating stacks of dielectric layers 122 and inner electrodes, which improves the inductance performance and electrical parameter stability of the device. The introduction layer 150 and the lead-out layer 120 respectively realize the stable input and output of electrode signals.

[0048] In some embodiments, the marking layer 110 serves to mark the stacked coil device, facilitating the differentiation of the upper and lower surfaces of the stacked coil device. To reduce parasitic capacitance and improve the quality factor (Q value), the total thickness of the insulating layer 140 near the lower substrate of the stacked coil device is relatively thick, and the marking layer 110 faces upwards during use. To reduce the number of stacked layers, the thickness of the marking layer 110 is less than the thickness of the insulating layer 140, and the thickness of the insulating layer 140 is set to 50μm to 80μm to prevent the parasitic capacitance from increasing and the Q value from decreasing.

[0049] The specific implementation of the present invention will be further described in detail below with reference to specific embodiments: Examples 1-24 and Comparative Examples 1-13 were prepared according to the parameters of the laminated coil device in Table 1. In Comparative Example 13, there is no crack 130 between the lead electrode 121 and the dielectric layer 122 in the lead layer 120, i.e., it is a conventional product. Wherein, w is the width of the crack 130. l h is the length of crack 130, and h is the height of crack 130.

[0050] Table 1 Parameters of Laminated Coil Devices

[0051]

[0052] After the preparation of Examples 1-24 and Comparative Examples 1-13 was completed, the performance data of Examples 1-24 and Comparative Examples 1-13 were tested according to the test items, test instruments and test methods in Table 2.

[0053] Table 2

[0054] It should be noted that for temperature cycling and damp heat aging tests, a stacked coil device is only tested once.

[0055] After the performance data tests of Examples 1-24 and Comparative Examples 1-13 were completed, the temperature cycling test results are shown in Tables 3 and 4. In these tables, the inductance value before temperature cycling or damp heat aging is L, the quality factor before temperature cycling or damp heat aging is Q, the contact resistance before temperature cycling or damp heat aging is R, the inductance value after temperature cycling or damp heat aging is L', the quality factor after temperature cycling or damp heat aging is Q', and the contact resistance after temperature cycling or damp heat aging is R'.

[0056] Table 3 Test results before and after temperature cycling

[0057]

[0058] Table 4 Test results before and after damp heat aging

[0059] It should be noted that the standards for the test results of the stacked coil device are as follows: the inductance value L is 119.5nh~120.5nh, the quality factor Q is ≥13.3, the contact resistance R is ≤2700mΩ, and the electrode peel strength before temperature cycling or damp heat aging is ≥2.1N.

[0060] As shown in Tables 3 and 4, after temperature cycling or damp heat aging, Examples 1 to 24 satisfy the following conditions: inductance value L' is 108nh to 132nh, quality factor Q' after temperature cycling or damp heat aging is 10.6 to 16, and contact resistance R' is ≤2835mΩ. Therefore, in this application, the width w of crack 130 is set to 30μm ≤ w ≤ the end width of lead electrode 121 and the length of crack 130. l Set to 5μm≤ l The height h of the crack 130 is set to 2μm≤h≤5μm, which can meet the production requirements of the stacked coil device.

[0061] Reference Figure 5 The second aspect of this application provides a manufacturing method for a laminated coil device based on the first aspect of this application, comprising the following steps: S100. Prepare dielectric layer slurry, internal electrode slurry and marker layer slurry according to the formula.

[0062] S200, Prepare the dielectric layer slurry into dielectric layer 122.

[0063] In step S200, a casting machine is used to form a dielectric layer 122 of the required thickness from the dielectric layer slurry.

[0064] S300. Using a first screen and internal electrode paste, lead-out electrodes 121 are formed on dielectric layer 122 to form lead-out units.

[0065] S400, using a second screen and marking layer paste to make marking layer 110.

[0066] In step S400, a marking layer 110 is formed on the medium layer 122 using a second screen and marking layer paste.

[0067] S500: The lead-out unit and the marker layer 110 are stacked in a preset stacking order to form a stacked whole.

[0068] Before step S500, the process further includes forming an inner electrode on the dielectric layer 122 using a third screen and an inner electrode paste to form an effective electrode region 160; forming an introduction layer 150 on the dielectric layer 122 using a fourth screen and an inner electrode paste; and forming an insulating layer 140 using the dielectric layer 122.

[0069] In step S500, the marking layer 110, the lead-out unit, the effective electrode region 160, the introduction layer 150 and the insulating layer 140 are stacked sequentially to form a stacked overall structure.

[0070] S600, the stacked whole is cut into multiple stacked bodies 100 green blanks, so that the lead-out unit of the lead-out layer 120 near the mark layer 110 forms a crack 130.

[0071] In step S600, the cutting blade is pressed into the laminated assembly, applying a preset pressure and a preset shear stress to the interface between the lead-out electrode 121 and the corresponding dielectric layer 122, causing the interface between the lead-out electrode 121 and the corresponding dielectric layer 122 to be in a subcritical damage state, and causing the material in the cutting area of ​​the cutting blade to undergo elastoplastic compression deformation, storing elastic strain energy; the cutting blade separates from the laminated assembly, and the elastic strain energy generates rebound tensile stress in the cutting area of ​​the cutting blade, and the superposition of the rebound tensile stress and shear stress exceeds the interface bonding strength between the lead-out electrode 121 and the corresponding dielectric layer 122, resulting in a crack 130 between the lead-out electrode 121 and the corresponding dielectric layer 122.

[0072] In step S600, when the cutting blade separates from the overall stack, the compressive stress applied to the dielectric layer 122 decreases sharply or even disappears. At this time, the compressive stress that previously played a dominant role disappears rapidly, and the elastic strain energy needs to be released. Therefore, a strong rebound tensile stress is generated at the interface perpendicular to the cutting surface of the cutting blade, and the residual shear stress is also released. At the moment of stress reversal, the interface that was previously in a subcritical damage state becomes fragile. The superposition of the rebound tensile stress and the shear stress exceeds the weakened interface bonding strength, so crack 130 is generated.

[0073] S700, sinter the green body of the laminate 100 to obtain the laminate 100.

[0074] In step S700, under an air atmosphere, the green blank of the laminate 100 is sintered at 800℃~900℃ and held for 20min~100min to form the laminate 100, and the crack 130 still exists after sintering.

[0075] S800: Connect the laminate 100 to the external electrode 200 to obtain a laminated coil device.

[0076] In step S800, the two ends of the sintered laminate 100 are coated with external electrode slurry, and the external electrode slurry enters the crack 130 to increase the connection reliability of the inner and outer electrodes; the laminate 100 is sintered at 500℃~700℃ and held for 5min~20min to form external electrodes 200 at both ends of the laminate 100.

[0077] The preparation method of this application embodiment involves preparing a dielectric layer 122 using a dielectric layer slurry, and fabricating lead-out electrodes 121 and a marking layer 110 using a first and a second screen printing plate, respectively. During the process of stacking the lead-out units and the marking layer 110 in a preset stacking order and cutting them into multiple stacked bodies 100 green blanks, a crack 130 can be formed between the lead-out electrode 121 and the dielectric layer 122 in the lead-out unit near the marking layer 110 of the lead-out layer 120. This allows for the formation of the crack 130 without additional complex processing steps, simplifying the fabrication process of the stacked coil device and improving mass production efficiency. Simultaneously, when the stacked body 100 is subsequently sintered and connected to the external electrode 200, the external electrode slurry 210 of the external electrode 200 can enter the crack 130 and connect to the corresponding lead-out electrode 121, improving the reliability of the connection between the internal and external electrodes of the stacked coil device, reducing the risk of open circuits and false connections in the stacked coil device, thereby improving the overall quality of the product and the mass production qualification rate.

[0078] The embodiments of this application have been described in detail above with reference to the accompanying drawings. However, this application is not limited to the above embodiments. Within the scope of knowledge possessed by those skilled in the art, various changes can be made without departing from the spirit of this application. Furthermore, unless otherwise specified, the embodiments and features described in the embodiments of this application can be combined with each other.

Claims

1. A stacked coil device, characterized in that, include: A laminate comprising a marker layer and an lead-out layer stacked sequentially, the lead-out layer comprising at least one lead-out unit, the lead-out unit comprising a lead-out electrode and a dielectric layer, the lead-out electrode being stacked with the dielectric layer, and the lead-out unit on the side of the lead-out layer near the marker layer having a crack, the crack being disposed between the lead-out electrode of the lead-out unit and the dielectric layer. An external electrode, wherein the external electrode slurry of the external electrode enters the crack and connects to the corresponding lead-out electrode.

2. The laminated coil device according to claim 1, characterized in that, The crack extends inward from the end corresponding to the lead-out electrode.

3. The laminated coil device according to claim 1, characterized in that, The width of the crack is denoted as w, and the width w of the crack satisfies the following relationship: 30μm≤w≤the end width of the lead-out electrode.

4. The laminated coil device according to claim 1, characterized in that, The length of the crack is denoted as l The length of the crack l Satisfies the relation: 5μm≤ l ≤20μm.

5. The laminated coil device according to claim 1, characterized in that, The height of the crack is denoted as h, and the height h of the crack satisfies the following relationship: 2μm≤h≤5μm.

6. The laminated coil device according to claim 1, characterized in that, The thickness of the lead-out electrode is set to 15μm to 25μm.

7. A method for preparing a laminated coil device according to any one of claims 1 to 6, characterized in that, Includes the following steps: Prepare dielectric layer slurry, internal electrode slurry, and marker layer slurry according to the formula; The dielectric layer slurry is used to form the dielectric layer; The lead-out electrode is fabricated on the dielectric layer using a first screen and the internal electrode paste to form the lead-out unit; The marking layer is made using a second screen and the marking layer slurry; The extraction unit and the marking layer are stacked in a preset stacking order to form a stacked overall structure; The stacked whole is cut into multiple stacked blanks such that the lead-out unit on the side of the lead-out layer near the mark layer forms the crack; The laminated body green body is sintered to obtain the laminated body; The laminated body is connected to the external electrode to obtain the laminated coil device.

8. The preparation method according to claim 7, characterized in that, The step of cutting the overall laminate into multiple green laminates such that the lead-out unit on the side of the lead-out layer near the marker layer forms the crack includes: The cutting blade is pressed into the stacked assembly; The cutting blade separates from the overall stack, and the crack is generated between the lead-out electrode and the corresponding dielectric layer.

9. The preparation method according to claim 7, characterized in that, The step of sintering the green body of the laminate to obtain the laminate includes: The green body of the laminate is sintered at 800℃~900℃ and held for 20min~100min to form the laminate.

10. The preparation method according to claim 7, characterized in that, The step of connecting the laminate to the external electrode includes: The two ends of the sintered laminate are coated with the external electrode slurry, and the external electrode slurry enters the crack; The laminate is sintered at 500℃ to 700℃ and held at that temperature for 5 min to 20 min, so that the two ends of the laminate form the external electrodes.

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